This application is the national phase under 35 U.S.C. xc2xa7 371 of PCT International Application No. PCT/EP98/05653 which has an International filing date of Sep. 7, 1998, which designated the United States of America.
This invention relates to a mechano-electronically operated cylinder-key unit for locks.
Mechanically operated cylinder-key units for locks are known. The cylinder comprises a metal body with a cylindrical portion and an appendix extending radially from this latter. Within the cylindrical portion there is provided a cylindrical seat housing a rotary plug provided with a plurality of radial recesses, which when in a predetermined angular position extend into recesses provided in the appendix. These recesses house axially movable pins divided into two portions, the separation surface of which, for a predetermined axial position of each pin in its respective recess, corresponds with the separation surface between the plug and its seat. This axial position, which is different for each pin, is determined by the pattern notches of a key inserted into a corresponding slot in the plug, and following this insertion enables the plug to be rotated, with consequent operation of the lock bolt via a pawl rigid with said plug.
This type of mechanically operated unit has been and is still widely used, but also has a series of drawbacks such as:
a limited degree of security because of the substantially limited number of possible key patterns;
the possibility of recognizing the key pattern xe2x80x9con sightxe2x80x9d;
key wear deriving both from use, because of the continuous rubbing between the cylinder and the teeth defining the key notches, and from key duplication, as a result of contact between the feeler and the patterned key to be duplicated;
cylinder sensitivity to atmospheric conditions.
To increase the degree of security of these known units it has been sought to make the key-cylinder interfacing mechanism increasingly more complicated so as to increase the number of possible patterns obtainable, but with this increase in pattern number there is a correspondingly lower reliability and strength of the unit.
For this reason, lock operating systems have been already proposed using electrical or electronic circuits able to electronically control a code memorized in the cylinder using a code memorized in the key or vice versa.
The need to use electrical power is a considerable inconvenience:
if the electronical power derives from the mains, difficulties arise in installing the lock and moreover the system can be used only if a mains supply is present, it becoming unusable if the supply fails; if however the electricity derives from a self-contained source, the state of its charge must be systematically checked.
To avoid these drawbacks it has been proposed to provide mixed units, ie mechanically operated but with an electronic control system powered by electrical energy generated by inserting the key into the lock cylinder or by rotating the key already inserted into it.
For example FR-A-2500520 (THOMSON-CSF) describes a unit of this type in which the electrical energy required for effecting key-cylinder recognition and for powering the electromechanical bolt release member on positive recognition is obtained by a piezoelectric effect by virtue of the action exerted on piezocrystals when the key is inserted, withdrawn or rotated, these being arranged along the lock channel.
A drawback of this arrangement is the very small amount of electricity produced, this generally being insufficient to satisfy the required electrical loads, which are themselves modest; a further drawback is the pulse nature of the electrical energy produced, incompatible with the particular type of electrical loads employed; a further drawback is the nature of the memorized code resident in the key and the method of transmitting the relative data to the reading, recognition and enabling circuits resident in the lock mechanism In this respect, if this code is of mechanical type and operates by pressure against appropriate feelers in the lock, it is easily decoded on sight; if it is of magnetic type it can be easily cancelled or altered; if it is of optical type it is very complicated and requires considerable energy for its operation.
U.S. Pat. No. 5,265,452 (DAWSON) describes a unit comprising a cylinder into which a key comprising a memorized code can be inserted and rotated. The rotation of the inserted key generates sufficient electrical energy to power the electrical circuit by which the lock recognizes the key code and, on positive recognition, to effect engagement between gearwheels enabling the lock bolt to be operated by the key.
This known solution, which inter alia is described in terms of general principles without any mention of the manner of energizing the electronic circuit provided in the key, or the reading and control arrangements provided external to the key, has the drawback of considerable constructional complexity and the practical impossibility of totally housing it within a traditional interchangeable European lock cylinder, hence limiting its application only to locks expressly constructed for this purpose.
EP-B1-0771381 (SILCA) describes an electromechanically operated cylinder-key unit for locks, using control and recognition logic housed partly in the key and partly in the lock, and mutually interacting via a connection without wires when the key is inserted into the lock, and further using, for the electrical energy required to power said logic, a generator which is operated on inserting the key into the cylinder and/or on rotating the cylinder by the key inserted into it.
This known solution has practically eliminated the previously recognized drawbacks, but at the same time has proved susceptible to improvement, in that:
the electrical energy is not generated uniformly, but is instead related to the mechanical torque applied to the key to rotate the generator, and to the angular velocity imposed by the key by virtue of its rotation or to the velocity with which the key is inserted into the cylinder plug,
the electrical energy generation system, and in particular the combination of the energy transformers of the entire chain, is of very low efficiency,
consequently the energy available for effecting the mechanical connection between the key and the operating pawl of the lock bar is low and is often not able to adequately power the electromagnet which determines this connection.
These and other drawback are eliminated according to the invention through a mechano-electronically operated cylinder-key unit for locks a mechano-electronically operated cylinder-key unit for locks, comprising a cylinder having a pawl which operates a bar and housing an electrical energy generator for powering an electronic circuit provided in said cylinder and for powering, by way of an inductive coupling when said key is inserted into said cylinder, an electronic circuit provided within said key, both said electronic circuits being provided with control logic for their recognition and for allowing, on positive recognition, said operation of said pawl by said key wherein said cylinder comprises:
means for mechanically locking the pawl when said key is withdrawn or is not recognized,
an electrical generator activated by a triggering member when a predetermined extent of insertion of said key into said cylinder is exceeded, and
means for transforming, on positive recognition, the kinetic energy of said triggered generator, in a deactivation movement of said mechanical locking means.